What is a Dreamweaver DWT?
Dreamweaver MX (and later versions) include the ability to use Dynamic Web Templates (DWT) — essentially it is a way of having a master template layout which pages in your site are attached to. If you change the master layout, all of the pages are updated with that change. It also limits the ability to alter regions of your page which are marked as “un-editable” so that you can work on your pages without the worry of “nudging” something off track in the master layout. The capabilities provided with the DWT are highly recommended for anyone who has 10+ pages in their site.